1. Field of the Invention
This invention pertains to flapper valves, and particularly to flapper valves used for well completions.
2. Related Art
Flapper valves are often used in subsurface safety valves. Subsurface safety valves are used in wells to contain wellbore fluids, particularly in the event of emergency situations in which there is potential danger to personnel, equipment, or the environment.
The present invention improves flapper valves by providing a curved flapper and a seat, the flapper and seat each having complementary undulating and tapered perimeters, with sealing surfaces designed to maintain seal integrity under higher pressure, for a given outer diameter to inner diameter ratio, compared to prior art flapper valves.